Prunus plant named ‘VSL-2’

ABSTRACT

A new and distinct rootstock variety of  Prunus  named ‘VSL-2’ that is characterized by an absence of suckers, a vigorous growth habit, pink flowers, the ability to serve well as rootstock that is compatible with all other cherries, and the ability to propagate well by softwood cuttings, stool beds and meristem cuttings in vitro. In combination these traits set the new cultivar apart from all other existing varieties of  Prunus  rootstock.

Botanical classification: Prunus fruticosa×p. lannesiana.

Varietal denomination: ‘VSL-2’.

CROSS-REFERENCES TO RELATED APPLICATIONS

The application for the new invention Prunus Plant Named ‘VSL-2’ isco-pending with three other plant patent applications entitled PrunusPlant Named ‘VVA-1’, Ser. No. 09/880,952; Prunus Plant Named ‘LC-52’,Ser. No. 09/880,950; and Prunus Plant Named ‘VSV-1’ Ser. No. 09/880,951,having the same filing date and inventor.

BACKGROUND OF THE INVENTION

The present invention relates to the new and distinct cultivar knownbotanically as a hybrid of Prunus and referred to hereinafter as‘VSL-2’. The new invention was bred by the inventor at the BreedingStation in Krymsk, Russia.

The breeding program at the Breeding Station was established in 1976 andfunded by the government of the former Soviet Union for the purpose ofproducing new and improved prunus cultivars that propagate well bymethods of softwood cuttings, meristem cuttings in vitro, as well as bystool beds, and that serve well as rootstock that is compatible withother cherries.

In 1976 the inventor crossed the female Prunus fruticosa (not patented)with the male Prunus lannesiana (not patented) producing an inducedhybridization in a cultivated area of Krymsk, Russia. The resultingseedlings were observed and evaluated for ten years. In 1986 theinventor selected ‘VSL-2’ from these seedlings. The new cultivaroriginated as a single plant and is a hybrid cross between Prunusfruticosa (not patented) and Prunus lannesiana (not patented).

The closest comparison plants are the parent plants. ‘VSL-2’ isdistinguishable from the female parent Prunus fruticosa by largerleaves, greater vigor, pink flowers, sour fruit, and absence of suckers.‘VSL-2’ is distinguishable from the male parent Prunus lannesiana by theabsence of stipules, smaller size, dark red fruit, and the ease ofpropagation. The distinguishing traits that make ‘VSL-2’ unique from allother existing varieties of Prunus rootstock known to the inventor areease of propagation, absence of suckers and the ability to serve asrootstock that is compatible with all cherries known to the inventor.

‘VSL-2’ was first asexually propagated in 1986 by the inventor at theBreeding Station in Krymsk, Russia. The method used was softwoodcuttings. The distinguishing traits have been determined stable and arereproduced true to type in successive generations.

BRIEF DESCRIPTION OF THE DRAWING

The photograph is an illustration of the new variety, VSL-2.

SUMMARY OF THE INVENTION

The following traits have been repeatedly observed and represent thedistinguishing characteristics of the new cultivar. These traits incombination distinguish ‘VSL-2’ from all other existing varieties ofPrunus rootstock. ‘VSL-2’ has not been tested under all possibleconditions and phenotypic differences may be observed with variations inenvironmental, climatic, and cultural conditions, however, without anyvariance in genotype.

-   -   1. ‘VSL-2’ serves as rootstock that is compatible with all other        cherries.    -   2. ‘VSL-2’ propagates well by softwood cuttings, stool beds, and        in vitro.    -   3. ‘VSL-2’ does not produce suckers.    -   4. ‘VSL-2’ exhibits a dwarf form.    -   5. ‘VSL-2’ is vigorous.    -   6. ‘VSL-2’ differs from the female parent Prunus fruticosa by        increased vigor, large leaves, pink flowers, sour fruit, and        absence of suckers.    -   7. ‘VSL-2’ differs from the male parent Prunus lannesiana by its        smaller size, dark red, sour fruit, ease of propagation, and        absence of stipules.

BOTANICAL DESCRIPTION OF THE PLANT

The following is a detailed botanical description of the new rootstockvariety Prunus ‘VSL-2’. Observations, measurements, values, andcomparisons were collected in McMinnville, Oreg. from the inventor. Thenew variety was five (5) years old when described and was cultivated ina hot and moderately humid environment. The foliage, flower and fruitexhibited by this cultivar are of no economic or commercial value,therefore comparisons and botanical descriptions of the foliage, fruitand flower are made for identification purposes only. Mature specimens,as well as bareroot specimens, were unavailable for photographing at thetime this document was written. The color determinations are inaccordance with The R.H.S. Colour Chart of the Royal HorticulturalSociety, London, England except where general color terms of ordinarydictionary significance are used.

-   Botanical classification: Prunus ‘VSL-2’.-   Parentage: Prunus ‘VSL-2’ is an induced hybrid that resulted from    crossing the following plants.    -   -   Female parent.—Prunus fruticosa (not patented).        -   Male parent.—Prunus lannesiana (not patented).-   Type: Deciduous tree.-   Use: ‘VSL-2’ serves well as rootstock for all other cherries known    to the inventor.-   Soil: All soils.-   Light: Full sunlight.-   Fruit bearing: None.-   Crop time: Requires 3 years from a rooted cutting to achieve    finished product size ready to ship bareroot (1 year rootstock and 2    years with scion variety).-   Dimensions at crop time: 2.5 m in height and 2 m. in width.-   Vigor: 50-60% of standard using Prunus avium as standard (sweet    cherry seedling).-   Habit: Dwarf and erect.-   Hardiness: USDA Zone 5A.-   Cold tolerance: Excellent.-   Heat tolerance: Excellent.-   Disease resistance: No diseases observed; high resistance to mildew.-   Propagation: Propagation can be accomplished by softwood cuttings,    stool beds and meristem cuttings in vitro.-   rooting habit: Fine and fibrous initially. After 1 year, roots    become fleshy and thick.-   Time to initiate roots: 6 months is required to develop roots at    22-25° Centigrade.-   Disease and insect resistance: Normal resistance to disease and    insects.-   Trunk:    -   -   Trunk dimensions (at 3 years).—5 cm. in diameter and 20 cm.            in height above soil.        -   Trunk bark surface.—Glabrous surface.        -   Trunk bark color.—178B.        -   Lenticels.—Present.        -   Lenticel dimensions.—2-3 mm. in length and 1 mm. in width.        -   Lenticel shape.—Lens shaped.        -   Lenticel color.—198B.-   Branches:    -   -   Branch surface.—Glabrous surface.        -   Branch color.—175B.        -   Internode length.—5-10 cm. between nodes.        -   Branching angle at emergence.—70° angle.        -   Branching habit.—Freely branching.        -   Branch pubescence.—Absent.        -   Branch lenticels.—Present.        -   Lenticels.—Present on all branches.        -   Lenticel shape.—Lens shaped.        -   Lenticel color.—198B.        -   Lenticel dimensions.—2-3 mm. in length and 1 mm. in width.        -   Lenticel number.—9 per inch on 2-year old rootstocks.-   Leaves:    -   -   Arrangement.—Alternate and whorled.        -   Leaf length.—4-4.5 cm. in length.        -   Leaf width.—3-3.5 cm. in width.        -   Leaf shape.—Lanceolate.        -   Leaf apex.—Acuminate.        -   Leaf base.—Rounded.        -   Leaf color (adaxial surface).—135D.        -   Leaf color (abaxial surface.—136B.        -   Leaf surface (adaxial).—Glabrous surface.        -   Leaf surface (abaxial).—Glabrous surface.        -   Leaf margins.—Crenulate. Young leaves involuted.        -   Leaf division.—Simple.        -   Petiole dimensions.—1.2 cm. in length and 1 mm. in width.        -   Petiole color.—140C.        -   Petiole surface.—Glabrous.        -   Stipules.—Absent.        -   Leaf pubescence.—Absent.        -   Venation pattern.—Pinnate with prominent mid-vein.        -   Vein color (adaxial and abaxial surfaces).—135D.        -   Leaf texture.—Smooth texture.        -   Leaf strength.—Moderate strength.        -   Leaf appearance.—Glossy with young leaves involuted.-   Fruit:    -   -   Maturity.—Requires 60-65 days to mature.        -   Dates of picking.—Not a fruit crop. Fruit has no commercial            value.        -   Production.—Minimal.        -   Fruit form.—Globose.        -   Stem dimensions.—2-2.5 cm. in length and 1 mm. in width.        -   Stem color.—144A.        -   Skin color.—53A.        -   Skin surface.—Glabrous surface.        -   Lenticels.—Absent.        -   Flesh color.—53A.        -   Flesh texture.—Juicy.        -   Flavor.—Bitter.        -   Aroma.—None.        -   Seed number.—One drupe.        -   See shape.—Round.        -   Seed color.—164A.        -   Seed dimensions.—5-6 mm. in diameter and 5-6 mm. in length.        -   Keeping quality.—None.        -   Storage.—Not determined because the fruit has no commercial            value.        -   Use.—Fruit is not recommended for consumption and has no            commercial value.-   Flower:    -   -   Arrangement.—Solitary.        -   Flower shape.—Rotate.        -   Bud dimensions.—3 mm. in width and 3 mm. in length.        -   Bud color.—56C.        -   Time of bloom.—Flowers bloom at when plant is 1 year and            flowers last for 7-8 days.        -   Flower diameter.—2.5-3 cm. in diameter.        -   Flower depth (throat).—2-2.5 mm. in depth.        -   Bloom quantity.—40-50 flowers per branch.        -   Number of petals.—Five petals in number.        -   Fused or unfused.—Petals are unfused.        -   Petal shape.—Oval.        -   Petal margin.—Entire and wavy.        -   Flower color fully opened (upper and lower surfaces).—56D.        -   Dimensions of peduncle.—2 cm. in length and 1 mm. in width.        -   Color of peduncle.—144A.        -   Surface of peduncle.—Glabrous surface.        -   Calyx dimensions.—2-3 mm. in length and 7-8 mm. in width.        -   Calyx surface.—Glabrous surface.        -   Pubescence.—Absent.        -   Calyx color.—152A.        -   Number of sepals.—Five sepals in number.        -   Natural flowering season.—Spring.        -   Persistent or self-cleaning.—Self-cleaning.        -   Fragrance.—None.-   Reproductive organs:    -   -   Stamen number.—Polyandrous. 20-25 stamens and unequal            lengths.        -   Stamen color.—145C.        -   Anther shape.—Round with stamen attached at center of dorsal            surface.        -   Anther color.—9B.        -   Anther dimensions.—1 mm. in length and 1 mm. in width.        -   Amount of pollen.—Heavy amount.        -   Color of pollen.—9B.        -   Pistil.—One in number.        -   Pistil color.—144C.        -   Pistil dimensions.—1 cm. in length and 0.50 mm. in width.        -   Style color.—144C.        -   Style shape.—Elongate.        -   Style dimensions.—1 mm. in length and 0.50 mm. width.        -   Ovary dimensions.—2 mm. in length and 2 mm. in width.        -   Ovary color.—144B.        -   Ovary position.—Superior.

1. A new and distinct variety of Prunus plant named ‘VSL-2’, as hereindescribed and illustrated.